DES MOINES, Iowa (AP) — Republican presidential candidate Mitt Romney on Tuesday painted President Barack Obama as a reckless steward of the country’s economy and, as proof, pointed to “a financial crisis of debt and spending that threatens what it means to be an American.”

The likely Republican nominee offered a far-reaching indictment of Obama’s tenure and portrayed himself as a beacon of fiscal responsibility with the public and private sector experience to prove it.

“A prairie fire of debt is sweeping across Iowa and our nation, and every day we fail to act that fire gets closer to the homes and children we love,” Romney told supporters at a downtown Des Moines hotel. He emphasized an issue that’s a big concern of the middle-class voters from across the political spectrum he and Obama are wooing.

“This is not solely a Democrat or a Republican problem,” Romney added, a clear pitch to independent voters who will decide the election. “The issue isn’t who deserves the most blame, it’s who is going to do what it takes to put out the fire.”

The White House promptly dismissed Romney’s critique.

Press secretary Jay Carney blamed federal overspending primarily on Romney-backed tax cuts for the wealthy that were enacted during President George W. Bush’s administration and on the pricy wars in Iraq and Afghanistan. Carney said Romney wants to repeat policies that led to high deficits and the recession and to repeal Obama policies “that reversed the cataclysmic decline on our economy and that now has us growing for 11 straight quarters.”

The Romney campaign’s fresh focus on debt and spending came one day after Obama launched an effort to castigate his Republican rival’s business credentials as the presidential campaign entered a more critical phase six months before the election. Obama’s campaign and an allied group were unveiling advertisements in key battleground states that suggest Romney put profits over people during his tenure at Boston-based Bain Capital.

Romney let his advisers fight back on that front while he opened his own sharp critique of Obama during his first trip back to Iowa since the leadoff nominating caucuses in January. Both campaigns see opportunity in Iowa in their battle for the 270 electoral votes required to win the presidency.

Romney was in this general election battleground as Oregon voters got ready to hand him a chunk of delegates Tuesday night that would help him inch closer to the 1,144 needed to clinch the GOP nomination. He was scheduled to travel to Florida, another key swing state, on Wednesday, where he planned to continue pressing his economic philosophy.

In Des Moines, Romney described Obama’s approach as that of an “old-school liberal” who ballooned the debt he pledged to curb, and broke with the budget-cutting record of the previous Democratic administration of President Bill Clinton. Romney argued that Obama inflated the deficit with programs such as the 2009 economic stimulus and 2010 health care measure after promising to cut it sharply during his first presidential campaign.

“The consequence is that we are enduring the most tepid recovery in modern history,” Romney said. “The consequence is that the length of time it takes an unemployed worker to find a job is the longest on record.”

In contrast, Romney argued that he would reduce federal spending to 20 percent of the nation’s gross domestic product by the end of four years in office. The rate today is 24.3 percent. He also advocated looking for private sector solutions to government programs, and moving the implementation of some programs to states.

Most of what Romney proposed were repackaged plans he’d discussed throughout the primary campaign, including trimming Social Security benefits for wealthy seniors and eliminating duplicate programs to save money.

More broadly, Romney tried to establish a wide philosophical divide with Obama over expanding the role of the federal government. Romney has been criticized by Republicans for signing a measure requiring everyone in Massachusetts to obtain health insurance. With the speech, Romney sought to paint himself as a small-government advocate.

He also sought to counter the notion that he was a detached elitist, as the Obama campaign has sought to portray him, while also courting blue-collar and conservative Democrats in battleground states like Ohio and Michigan, where economic anxiety remains high. Obama struggled to attract those voters during his bid for the nomination four years ago, and he hasn’t locked them up this year either.

The public has broad concerns about the impact the national debt will have in the future. According to a Gallup poll conducted in February, 73 percent of Americans said they were “very concerned” about the impact of the amount of U.S. debt held by other countries’ on the U.S. economy.

When asked which candidate they trust to do a better job of handling the federal budget deficit, 51 percent sided with Romney, compared to 38 percent for Obama, according to an April ABC News/Washington Post poll.

Yet polls show spending and the debt distantly trailing jobs and the economy as the top campaign issue.

Still, May DeHaan, a Des Moines-area Romney supporter who attended his speech, said it’s all one issue.

“They are totally entwined. The government can’t continue to pay for things when people don’t have jobs,” said DeHaan, who works for a Des Moines insurance company.